Just for fun, I found some other ideas across the internet.
Since bear hugs are a good thing to share for Valentine's, you might consider this happy little bear from Making Friends.
But my absolute favorite (so far) this year is the hardy pirate ship by My Party Bug. Can't you just imagine your little swashbuckler beaming with pride when carrying this into the classroom? http://www.mypartybug.com/blog/?cat=6
Whatever design they choose (even if it's stickers on a bag) Valentine's is a great chance for kids to show their friends they care. Have fun, and Happy Heart Day!